This invention relates to a plurality of artificial teeth supported by a plurality of implants, and more particularly to a means and method of preparing a rigid metal bar that is fitted to implants embedded in the bone. The bar, in turn, supports a dental prosthesis with many teeth, all installed on the same day as surgical installation of the implants.
When a tooth is missing, it is often useful to surgically insert a metal implant screwed into the bone to support an artificial tooth. Recent developments in the art have made it possible to complete the surgical implantation and installation of the tooth on the same day. When many teeth are to be replaced, it is common to prepare a rigid metal bar or bridge to be fastened to a plurality of implants. A denture with many replacement teeth is then fastened to the metal bar. This makes it possible to support many teeth, with as few as three implants. It also enables the forces on the teeth to be distributed onto many implants at once for greater resistance to damage to the restoration. Branemark et al. describe a system of this sort that may be completed on the day of surgery. That method involves the use of a primary bar and a secondary bar with holes positioned for receipt of retaining screws. The soft tissue over the bone is moved away to expose the bone. The crest of the bone is then planed flat to correspond to the bottom of the primary bar. The bar is held in place on the bone to serve as a template or drill jig for drilling the holes for the implants at the holes in the bar. The bar is removed, the holes drilled into the bone, and the implants screwed into the bone. The implants are each fitted with a collar that passes through the soft tissue and the soft tissue closed over the bone and sutured in the usual manner. A dental plate, or denture, is attached to the secondary bar. After the implants have been inserted surgically, the primary bar is screwed onto the implants and the secondary bar with attached denture is screwed onto the primary bar.
It would be useful to avoid having to expose and plane the crest of the large bone area as required by this procedure. Practitioners of the art are expert at finding the most suitable area for insertion of each implant for best results. This procedure dictates the location of the implants. Many dentists would prefer to have a denture prepared in advance by a dental laboratory, and to be able to position the implants based on the patient""s situation.
It is accordingly an object of the invention to provide a means and method of supporting a dental prosthesis with many artificial teeth on a lesser number of surgically inserted implants, in which the entire procedure of insertion of implants and supporting the prosthesis thereon can be achieved in one day without the necessity of planing the crest of the bone or dictating the location of the implants. It is another object that the prosthesis may be prepared prior to the day of surgery, so that it may be prepared by an outside laboratory. It is yet another object that the means include a rigid metal bar that is fitted to the implants and that will support the prosthesis. It is yet another object that the bar be composed of a plurality of prefabricated individual components each of which fits onto an implant and that has projecting elements. It is yet another object that the projecting elements be cementable together while mounted on the implants to fix the bar geometry. It is yet another object that the elements be securely affixed together by soldering, welding or other permanent metal joining means without altering the bar geometry so that the rigid metal bar can be custom made to fit the patient on the day of operation.